Walk-though flat barn parlor

ABSTRACT

A walk-through flat barn parlor comprises a number of modular stalls for managing dairy cows. Each module has a frame to which a pair of gates are mounted. The axes of rotation for the gates make compound angles with the vertical such that the gates are biased by gravity to rotate from a closed mode to a ready open mode. A control mechanism is actuated by a cable mechanism from a milking station to unlock the gates for automatic rotation by gravity from the closed mode to the ready open mode. A cow walks to the ready open gates and pushes them to the closed mode, where she is constrained for milking. After completion of milking, the farmer actuates the cable mechanism to unlock the gates and enable the cow to push them to an exit open mode. When the cow has cleared the gates, they automatically rotate by gravity back toward the closed mode. A pawl on a bar connecting the gates co-acts with the control mechanism to enable the gates to rotate past the closed mode all the way to the ready open mode. The cable mechanism includes a reversing mechanism that enables the farmer to actuate the control mechanism in a consistent manner regardless of the side of the stall his milking station is located.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention pertains to agricultural equipment, and more particularlyto apparatus useful in animal husbandry.

2. Description of the Prior Art

Handling large animals such as swine and cattle is a difficult and evendangerous job. The animals are far stronger than the persons trying tomanage them, so mechanical aids are commonly employed to direct desiredanimal movements. Examples of large animal managing equipment includevarious squeeze chutes manufactured by For-Most, Inc. of Hawarden, Iowa,and by Palco, Inc. of Belle Plaine, Iowa.

A very important application of large animal management concerns dairycows. For efficient milking, the cows must be calmly constrained atspecific locations. Various equipment, such as stanchions, have beendeveloped to constrain the cows in place, not only for milking but alsofor treating them for injury or illness.

In addition to the specific equipment that physically constrains cows atdesired places for milking, the general milking environment hasundergone continuous development over the years. Many dairy barns nowinclude a pit parlor having stalls in which the cows stand at anelevation higher than that of the farmer. Headgates of various types areemployed to firmly constrain the cows in the stalls while they aremilked. The headgates are also useful for constraining the cows formedical or other treatment. The milking equipment is integrated into theparlors such that it remains in the same place during the entire milkingoperation. The idea is to move the cows to and from the milkingequipment at the stalls and not move the milking equipment to and fromthe cows. Another advantage of pit parlors is that the farmer can workwithout bending and stooping to clean, milk, and treat his cows.

Although pit parlors greatly increase efficiency, they suffer thedisadvantage of being very costly to install. Consequently, onlyrelatively large operations can afford them. Moreover, the farmer mustremain on his feet during the entire milking operation.

In an effort to obtain the benefits of pit parlors without theirexpense, flat barn parlors have recently been developed. In flat barnparlors, the farmer and the cows walk on the same barn surface, i.e.,the barn floor. Accordingly, a new building or major changes to a barnfloor or foundation are not required, which is a substantial costbenefit.

Some milking stalls of flat barn parlors are designed with headgatesthat open in only one direction. A headgate is operated to accept thehead and neck of a cow and then closed and locked during milking orother procedures. For the cow to leave the stall, she must back up afterthe farmer has unlocked the headgate. That action is undesirable forseveral reasons. Some animals are reluctant to walk backwards, so theymust be prodded to do so. Some cows tend not to walk straight back, sothey often bump into the milking equipment. Consequently, the farmermust guide the cow backwards. Since the next cow cannot enter the stalluntil the previous cow is completely out of the way, congestion at thestall is inevitable. The time necessary for the farmer to clear a cowfrom the stall is wasted.

A better type of headgate is one that opens in two directions. Theheadgate opens to a ready position to accept the cow's head and neck,and the headgate locks at a closed position. When the farmer unlocks theheadgate, the cow is able to walk forward, forcing the headgate open toan exit position. That design greatly improves cow traffic byeliminating the problems associated with backing a cow out of her stall.

However, prior walk-through headgates are not entirely satisfactory.They tend to remain open after the cows have passed through them, so thefarmer must leave his milking station to close them. That activityrepresents non-productive time. In an attempt to make headgatesself-closing, different types of spring and pneumatic mechanisms havebeen employed. The prior spring and pneumatic actuated headgates havenot proven completely reliable. Further, the springs or pneumaticdevices swing the headgates with undesirably high speeds such that theybang closed with a noisy shock. The farmer still must manually open aclosed headgate to the ready position to accept the next cow. Finally,the springs exert uncomfortable forces on the cow's shoulders, sides,and pins as she pushes the headgate open and walks through it whenleaving the stall.

Thus, a need exists for improvements in animal headgates.

SUMMARY OF THE INVENTION

In accordance with the present invention, a walk-through flat barnparlor is provided that greatly increases the efficiency of managingdairy cows and other large animals. This is accomplished by apparatusthat includes headgates that automatically operate by gravity from anexit open mode to a ready open mode.

The walk-through flat barn parlor preferably comprises several modularstalls that are arranged to suit the space available in a barn orsimilar enclosure. Each modular stall comprises a frame and a headgatehinged to the frame. Dividers are mounted to the frames of adjacentmodules. The dividers stationarily support milking or other equipment.

The headgate of each stall module comprises two separate gates, eachhinged to the frame for rotation about respective axes of rotation. Thegates rotate together in opposite directions between the ready openmode, the exit open mode, and a closed mode intermediate the ready openand exit open modes. In the ready open mode, the gates are partiallyopened toward an upstream direction from which a cow walks to the stall.In the exit open mode, the gates are fully opened in a downstreamdirection taken by the cow when she leaves the stall. The operation ofthe gates is controlled by a control mechanism actuated by the farmerfrom a milking station by means of a manually operated cable mechanism.

The control mechanism is assembled to the frame and comprises first andsecond latches, first and second actuating angles, and a lever. Thefirst and second latches rotate about respective horizontal axes betweenraised and lowered positions. When the latches are in their loweredposition, they capture between them tabs on the gates in a manner thatlocks the gates in the closed mode. When either latch is in a raisedposition, the gates can rotate past that latch.

It is a feature of the present invention that the gates are biased bygravity to rotate from the closed mode toward the upstream direction tothe ready open mode. For that purpose, when the gates are in the closedmode, they lie in a plane that makes an angle of several degrees to thevertical. The plane of the gates is directed upwardly and toward theupstream direction.

To unlock the gates and enable them to rotate from the closed mode tothe ready open mode, the first latch is rotated to its raised position,thus removing the restraint of that latch from the gate tabs. To rotatethe first latch to its raised position, the cable mechanism ismomentarily actuated in a first direction by the farmer. That actiontilts the lever to a first actuated attitude and causes the firstactuating angle to pivot to an actuated condition. Pivoting theactuating angle lifts a finger joined to the first latch, therebyrotating the first latch to its raised position. At the raised position,the latch is clear of the gate tabs. The gates then automatically rotateby gravity toward the upstream direction to the ready open mode. Theamount of gate rotation at the ready open mode is adjustably governed bya stop mechanism. Release of the cable mechanism after actuation allowsthe first latch to rotate by gravity back to its lowered position.

To reclose and lock the gates, it is necessary merely to push them tothe closed mode, which is normally done by a cow entering the stall. Animportant aspect of the present invention is that the cow's movement inthe downstream direction within the stall is carefully controlled suchthat she walks sufficiently far into the stall to lock the gates at theclosed mode. To assure that the cow does walk downstream sufficientlyfar, the dimension from the gates to the back of a raised platform ofthe stall is carefully controlled. The tabs on the closing gates cam thefirst latch from its lowered position to its raised position until thetabs move past the first latch; then the first latch rotates again bygravity to its lowered position, where it cooperates with the secondlatch to again capture the gate tabs and lock the gates.

To enable the gates to rotate from the closed mode to the exit openmode, the farmer actuates the cable mechanism in a second direction.Doing so tilts the lever to a second actuated attitude and causes thelever to pivot the second actuating angle to an actuated condition andraise a finger joined to the second latch. The second latch rotates toits raised position and clears the gate tabs. The gates can then bepushed to the exit open mode by a force that normally comes from a cowleaving the stall in the downstream direction. The amount of rotation ofthe gates to the exit open mode is governed by the stop mechanism. Afterthe farmer releases the cable mechanism, the second latch rotates bygravity to its lowered position.

In carrying out the present invention, the axes of rotation of therespective gates converge upwardly by a few degrees. Consequently, thegates are biased by gravity to start rotation from the exit open modeback toward the closed mode. It follows that as soon as the cow haspassed by the open gates, they automatically rotate by gravity back fromthe exit open mode toward the closed mode. The gate tabs cam the secondlatch to its raised position to enable the gates to reach the closedmode.

In the preferred embodiment, the control mechanism is designed such thatthe farmer actuates the cable mechanism in the same direction forselectively unlocking the gates for rotation to either the ready openmode or the exit open mode regardless of where the cable mechanism isinstalled within the walk-through flat barn parlor. That is achieved bya reversing mechanism composed of a link that oscillates within theframe and a rod connecting a first end of the link to the controlmechanism lever. One end of a flexible cable is assembled to either thefirst or a second end of the link. The placement of the link relative tothe control mechanism and the link end to which the flexible cable isassembled to the link depends on the location of the cable relative tothe stall. The other end of the flexible cable has a hand knob foractuation by the farmer.

Further in accordance with the present invention, the gates do notbecome locked at the closed mode when they rotate from the exit openmode to the closed mode. Rather, a pawl in a bar that connects the gatesto each other strikes the first actuating angle as the gates approachthe closed mode. The pawl pivots the first actuating angle in a manneridentical to the pivoting thereof by actuation of the cable mechanism.The pivoting first actuating angle lifts the finger joined to the firstlatch and thereby rotates the first latch to its raised position. As aresult, the gate tabs pass the first latch without contact therewith,and the gates rotate completely to the ready open mode.

In normal use, the farmer actuates the cable mechanism only to release acow from the locked gates. As the cow walks forwardly in the downstreamdirection, she opens the gates to the exit open mode. As soon as sheclears the gates, they automatically rotate by gravity to the ready openmode. The next cow rotates the gates to the closed mode, where theybecome locked so that the cow is restrained until the farmer againactuates the control mechanism to release the cow.

The method and apparatus of the present invention, using gravity toautomatically rotate a headgate between exit open and ready open modes,thus enables a farmer to manage the movements of large animals with easeand efficiency. A control mechanism is actuated a single time to bothrelease the animal from the headgate and to ready the headgate withoutmanual manipulation thereof for accepting and constraining the nextanimal.

Other advantages, benefits, and features of the present invention willbecome apparent to those skilled in the art upon reading the detaileddescription of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of the walk-through flat barn parlor of the presentinvention.

FIG. 2 is a front view of FIG. 1.

FIG. 3 is a view on an enlarged scale taken along line 3--3 of FIG. 1and rotated 90 degrees clockwise.

FIG. 4 is a partial view on an enlarged scale taken along line 4--4 ofFIG. 3.

FIG. 5 is a simplified view taken along line 5--5 of FIG. 4 showing theheadgate in the closed mode.

FIG. 5A is a view similar to FIG. 5, but showing the headgate in theready open mode.

FIG. 5B is a view similar to FIG. 5, but showing the headgate in theexit open mode.

FIG. 6 is a cross sectional view on an enlarged scale taken along line6--6 of FIG. 3.

FIG. 7 is a partially broken view on an enlarged scale taken along line7--7 of FIG. 3.

FIG. 8 is a cross sectional view on enlarged scale taken along line 8--8of FIG. 7.

FIG. 9 is a cross sectional view on an enlarged scale taken along line9--9 of FIG. 7.

FIG. 10 is a cross sectional view on enlarged scale taken along line10--10 of FIG. 7.

FIG. 11 is a view similar to FIG. 10, but showing the control mechanismactuated to enable the headgate to rotate to the ready open mode.

FIG. 12 is a view similar to FIG. 10, but showing the control mechanismactuated to enable the headgate to rotate to the exit open mode.

FIGS. 13A-13D are simplified schematic drawings of the operationalrelation between the actuating angles and the pawl of the controlmechanism.

FIG. 14 is a view on an enlarged scale taken along line 14--14 of FIG.7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Although the disclosure hereof is detailed and exact to enable thoseskilled in the art to practice the invention, the physical embodimentsherein disclosed merely exemplify the invention, which may be embodiedin other specific structure. The scope of the invention is defined inthe claims appended hereto.

GENERAL

Referring first to FIGS. 1-3, a walk-through flat barn parlor 1 isillustrated that includes the present invention. The walk-through flatbarn parlor 1 is particularly useful for managing dairy cow trafficduring milking operations. However, it will be understood that theinvention is also eminently suited for handling large non-dairy animalswhile nursing, breeding, or otherwise treating them.

For illustrative purposes the walk-through flat barn parlor 1 isdepicted as having a number of stalls 2 arranged in two parallel rows 3and 5. The rows 3 and 5 of stalls 2 are separated by a central aisle 6.The stalls have raised platforms 4 that are approximately six inches tonine inches higher than the level of the central aisle 6. Each platform4 has a vertical wall 10 adjacent the central aisle. Each row of stallscomprises a number of stall modules 8 joined end to end. Each module 8includes a frame 7 that defines a generally vertical plane 9. Thehorizontal distance from the plane 9 to the walls 10 of the stallplatforms 4 is carefully controlled. The exact dimension will varydepending on the size and type of animals managed by the walk-throughflat barn parlor 1. As an example, for Holstein dairy cows, thedimension is between approximately 62 inches and 67 inches. Dividers 11are mounted to the frames 7 of adjacent stall modules. The milkingequipment, not shown but well known in the art, is stationarily locatedwithin the dividers 11. Each stall module also includes a headgate 13.Each stall of the walk-through flat barn parlor thus has a headgate 13at one end, and the other end of the stall is open to the central aisle6.

Cows typically enter the walk-through flat barn parlor 1 through a gate16 and walk into the central aisle 6. From the central aisle, the cowswalk from an upstream direction to any empty stall 2, as is indicated bythe arrows 15.

The headgate 13 of each stall 2 is selectively controlled by anassociated control mechanism 14 to alternately gently receive andconstrain a cow by her neck, and to release the cow. The controlmechanism 14 is assembled in the frame 7 above the associated headgate13, but the control mechanism is actuated by the farmer from his milkingstation at a divider 11 by means of a cable mechanism 85. While the cowis constrained, she can be milked or otherwise treated. When milking iscompleted, the headgate is controlled to release the cow for walkingforwardly in a downstream direction indicated by arrows 17 away from thewalk-through flat barn parlor 1. Another cow can then immediately enterthe stall from the central aisle 6 to take the place of the departedcow.

FRAME AND DIVIDERS

In the illustrated construction, the frame 7 of each stall module 8 ismade up of two upright posts 19 lying generally in the vertical plane 9.The lower ends of the posts 19 are firmly anchored to the platform 4 byany suitable means. The frame further includes a side brace 23 bolted orotherwise secured to each post. The braces 23 are also anchored to theplatform 4, and, if convenient, they may also be secured to existingvertical barn supports 20. A vertically oriented plate 24 is welded tothe upper end of each post. Also see FIG. 7. Extending between andsecured to the plates 24 is an open top housing 21, which includes acover 12. Preferably, the housing 21 is secured by end walls 28 thereofto the plates 24 by conventional fasteners 26.

Mounted to the posts 19 of the modules 8 are the dividers 11. Thedividers tie the modules together and space them along the rows 3 and 5of the walk-through flat barn parlor 1. The dividers are preferablymanufactured from round steel tubes 22 that are bent into a loop. Thefree ends of the tubes 22 are mounted to the frame posts of adjacentmodules, and the tube bent ends 25 extend toward the central aisle 6.Vertical legs 27 help support the tubes 22. A swivelable stool 29 ofadjustable height is supported from the vertical leg 27 of each divider.As mentioned, well known milking equipment, prepping equipment, andrelated supplies are installed within the dividers.

HEADGATE

Each of the headgates 13 of the walk-through flat barn parlor 1 iscomprised of two symmetrical gates 31 and 33. Each gate 31 and 33 has along tube 35 that is supported at its lower end 40 on an associated post19 of the frame 7 and at its upper end 57 by the housing 21. Each gatealso has a top horizontal tube 37. Near the free end of each tophorizontal tube 37 is welded an upstanding tab 36.

The gates 31 and 33 rotate together in opposite directions aboutrespective axes 55 as is illustrated in FIGS. 5, 5A, and 5B. In FIG. 5,the gates are in a closed mode such that their respective top tubes 37are parallel to the plane 9. In FIG. 5A, the gates have rotated in thedirections of arrows 38 to a ready open mode, whereat they are partiallyopen toward the central aisle 6 of the walk-through flat barn parlor 1(FIG. 1). When in the ready open mode, the gate top tubes 37 make anangle of approximately 35 degrees with the plane 9. In FIG. 5B, thegates have rotated in the directions of arrows 42 to an exit open mode.In the exit open mode, the gates are fully opened in the downstreamdirection 17 away from the central aisle, and the top tubes make anangle of approximately 90 degrees with the plane 9. The location of thegates at the exit open and ready open modes is governed by a stopmechanism 44 (FIG. 7) to be described presently.

It is a feature of the present invention that the gates 31 and 33 arebiased by gravity to rotate from the closed mode to the ready open mode.Looking especially at FIGS. 4, 6, and 8, the axes of rotation 55 of thegates make an angle with the plane 9 such that the axes lean upwardlytoward the central aisle 6 of the walk-through flat barn parlor 1. Theangle of the axes 55 relative to the plane 9 may be betweenapproximately five and eight degrees; an angle of six degrees works verywell. Consequently, when the gates are in the closed mode, they lie in aplane 39 that is not parallel to the plane 9 of the frame 7. Rather, theplane 39 also leans upwardly toward the central aisle at the same angleas the axes of rotation 55.

Similarly, the gates 31 and 33 are biased by gravity to rotate from theexit open mode to the closed mode. It will be noticed from FIG. 3 thatthe axes of rotation 55 of the gates 31 and 33 converge upwardly. Theangle of convergence shown is exaggerated for clarity; the actualincluded angle of convergence is preferably between approximately twoand six degrees, with two degrees being satisfactory. The axis ofrotation 55 of each gate tube 35 thus makes a compound angle relative tothe vertical: a six degree angle with respect to the plane 9 indirections perpendicular to that plane, and a one degree angle indirections parallel to that plane.

To support the gates 31 and 33 at the six degree and one degree compoundangles, the lower end 40 of the tube 35 of each gate is rotatablysupported on an associated bracket 41 that is welded or otherwiseattached to a frame post 19. The bracket 41 has a leg 43 that make a sixdegree angle with the vertical in directions perpendicular to the plane9 and a one degree angle with the vertical in directions parallel to theplane 9. The bracket leg 43 defines a slot 45 that accepts a screw 47.The screw 47 has head 48. The screw passes through a cylindrical plug49. The plug 49 is made of a synthetic material such as reprocessedpolystone M plastic. A nut 50 threaded onto the threads of the screw 47firmly holds the synthetic plug 49 to the bracket leg 43. A socket inthe threaded end of the screw 47 enables the nut 50 to be turned tightlyonto the screw threads. The lower end 40 of the tube 35 includes a disk51 welded to the interior of the tube 35 to create a recess 52. The plugis placed into the tube recess 52, with a washer 53 interposed betweenthe plug and the disk 51. In that manner, the lower end 40 of the tube35 is mounted to the frame for rotation about the plug. Merely byloosening the nut 50, the lower end of the gate and the plug can be slidout from the bracket 41.

The upper end 57 of the tube 35 of each gate 31, 33 is supported in thehousing 21, as best shown in FIGS. 7 and 8. For that purpose, a shortshaft 59 is adjustably held within a bushing 61 that is welded to thetube upper end 57. The shaft 59 is journaled in a conventional sphericalflange bearing 63, which is attached by fasteners 65 to the housingfloor 96. The brackets 41, plugs 49, and spherical flange bearings 63thus cooperate to define the axes of rotation 55 of the gates that makethe compound angles of six degrees and one degree with the vertical.

To synchronize rotation of the two gates 31 and 33 of the headgate 13 inopposite directions, the tubes 35 of the gates are connected to eachother by a linkage 67. The linkage 67 comprises two arms 69, 70 weldedeach to a shaft 59. The free ends of the arms 69 are connected, as by ascrew, washer, spacer, and nut collectively shown at reference numeral71, to the bearing of a spherical rod end 73. The threaded ends of thespherical rod ends 73 are adjustably threaded into opposite ends of along connecting bar 74. Thus, the gates rotate together and in theopposite directions of arrows 38 and 42. We have found that the anglesbetween the gate top tubes 37 and the arms 69 and 70 are important. InFIG. 7, the linkage 67 is shown in its position when the gates are inthe closed mode. In that situation, the arm 69 makes an angle ofapproximately 55 degrees with the gate top tubes, and the arm 70 makesan angle of approximately 65 degrees with the gate top tubes, with thearms 69 and 70 lying on opposite sides of the connecting bar 74.

As best shown in FIG. 7, the connecting bar 74 translates generally inthe direction of arrow 76 when the gates rotate in the directions ofarrows 38. The connecting bar translates generally in the direction ofarrow 78 when the gates rotate in the directions of arrows 42.

CONTROL MECHANISM

The operation of the headgate 13 of each stall module 8 is controlled bythe control mechanism 14. Looking especially at FIGS. 7, 9, and 10, thecontrol mechanism is assembled to the housing 21 and is comprised offirst and second latches 75 and 77, respectively, first and secondactuating angles 79 and 81, respectively, and a lever 83. The latches 75and 77 are acted upon by the actuating angles 79 and 81 under theinfluence of the lever 83 and a cable mechanism 85 to selectivelyprevent or allow rotation of the gates 31 and 33.

In the illustrated construction, each latch 75 and 77 is comprised of apair of flat plates 87 welded to each other along one edge 89 and attheir opposite edges to a tube 91. The tube 91 of each latch fits freelyover a respective horizontal shaft 93 that is supported on its oppositeends in the walls of an open bottom box 95. The box 95 is bolted to theunderside of the floor 96 of the housing 21. The latch 75 is thus freeto rotate about a horizontal axis in the directions of arrows 98 and100, and the latch 77 is free to rotate in the directions of arrows 102and 104. Gravity tends to rotate latch 75 in the direction of arrow 98and latch 77 in the direction of arrow 104. A high nut 97 is welded tothe latch 75, and a similar high nut 99 is welded to the latch 77.Adjustably screwed into the high nut 97 of the latch 75 is one end of afirst finger 101; the other end of the finger 101 forms a hook 106. Ajam nut holds the finger 101 in place. A similar finger 103 with a hook108 is screwed into the high nut 99.

The first actuating angle 79 is comprised of a tube 105 and a pair oflegs 107 and 109. The legs 107 and 109 are perpendicular to each otherand are fixed to the tube 105. The tube 105 is supported on a shaft 110.In turn, the shaft 110 is supported, as by screws 113, between a sidewall 111 of the housing 21 and the vertical leg 112 of an angle 114. Thelower end of the angle leg 112 is welded to the housing floor 96. Theother angle end 118 is welded to a top flange 120 of the housing.

In FIG. 10, the first actuating angle 79 is shown in a normal condition,whereat the leg 109 is horizontal and the leg 107 is vertical.Counterclockwise rotation of the first actuating angle with respect toFIG. 10 is prevented by contact of the leg 109 with the housing floor96. The finger 101 passes through a hole 116 in the housing floor. Thefinger hook 106 overlies the leg 109 of the first actuating angle. Thus,the first actuating angle and the finger 101 cooperate to prevent thefirst latch from rotating in the direction of arrow 98 past a loweredposition as shown in FIG. 9. That is, the first actuating angle and thefinger 101 cooperate to retain the latch 75 at its lowered positionagainst rotation due to gravity in the direction of arrow 98 when thefirst actuating angle is in its normal condition.

The second actuating angle 81 has a tube 117 that is free to rotate overthe shaft 110. A first leg 119 of the second actuating angle ishorizontal and a second leg 121 is vertical when the second actuatingangle is in a normal condition as shown in FIGS. 9 and 10. Clockwiserotation of the second actuating angle with respect to FIG. 10 isprevented by contact between the leg 119 and the housing floor 96. Thefinger 103 passes through a hole 123 in the housing floor. The hook 108of the finger 103 overlies the leg 119 of the second actuating angle.Consequently, the second actuating angle and the finger 103 cooperate toretain the latch 77 in the lower position thereof of FIG. 9 againstrotation due to gravity in the direction of arrow 104 when the secondactuating angle is in its normal condition. There is an opening 115 inthe housing floor 96 under the actuating angles 79 and 81 that permitspivoting of the actuating angles.

The lever 83 is preferably h-shaped, having a first leg 124, a secondleg 127, a cross leg 130, and an upstanding bar 129. The first andsecond legs 124 and 127, respectively, are supported for rotation on theshaft 110. In FIG. 10, the lever is shown in a normal attitude.

When the latches 75 and 77 are in their respective lowered positions ofFIG. 9, they capture between their respective free ends 89 the tabs 36on the top tubes 37 of the gates 31 and 33. The latches are so locatedthat the gates are in their closed mode of FIG. 5 when the tabs arecaptured between the latches. Because of the six degree angle that theplane 39 of the closed gates makes with the vertical, the gates tend torotate by gravity about their respective axes 55 toward the ready openmode of FIG. 5A. Consequently, the gate tabs 36 bear against the latch75 when the gates are in the closed mode.

To enable the gates 31 and 33 to rotate from the closed mode to theready open mode, the latch 75 is rotated about its shaft 93 in thedirection of arrow 100 to a raised position as shown by phantom lines128, FIG. 9. Raising the latch 75 is achieved by pivoting the firstactuating angle 79 in a clockwise direction, arrow 132, relative to FIG.10 to an actuated condition as shown in FIG. 11. Pivoting the firstactuating angle to its actuated condition causes the leg 109 thereof tolift the finger 101 and thus rotate the latch 75 to its raised position.The first actuating angle, finger, and latch are so dimensioned thatapproximately a 45 degree pivoting of the actuating angle raises thelatch sufficient to clear the gate tabs 36. Accordingly, the gatesbecome unlocked to automatically rotate by gravity in the directions ofarrows 38 in FIG. 5 to the ready open mode. In FIG. 9, the phantom line125 represents the plane of the tops of the tabs as the gates rotate.

To enable the headgate 13 to rotate to the exit open mode of FIG. 5Bfrom the closed mode of FIG. 5, the second actuating angle 81 is pivotedcounterclockwise with respect to FIG. 10 to the actuated condition ofFIG. 12. Pivoting the second actuating angle lifts the finger 103 by itshook 108 and thereby rotates the second latch 77 in the direction ofarrow 102, FIG. 9, to its raised position. The gates 31 and 33 can thenbe manually pushed to rotate them in the directions of arrows 42, FIG.5, to the exit open mode of FIG. 5B.

STOP MECHANISM

To govern the location of the headgate 13 when it is in the ready openmode of FIG. 5A and in the exit open mode of FIG. 5B, the stop mechanism44 forms a part of the modular stall 8. The operation of the stopmechanism is best understood upon reference to FIGS. 7 and 9. A lug 163is fixed to the connecting bar 74 near one of its ends. Welded orotherwise attached to the angle 114 and to the housing 21 is a flatplate 167. On the side of the plate 167 opposite the lug 163 isfastened, as by screws 169, a guide bumper 171. The bumper 171 may bemanufactured from the same reprocessed polystone M synthetic plasticmaterial as the plugs 49 used to guide the lower ends 40 of the gates 31and 33 (FIG. 6). The bumper 171 and the plate 167 have concentric holestherethrough. The hole in the bumper is shown at reference numeral 175.

One end of a stop rod 165 is adjustably and swivelably connected to thelug 163 by means of a threaded clevis 166. The stop rod 165 passesthrough and is loosely guided in the hole 175 in the bumper 171. Thehole in the plate 167 provides clearance for the stop rod.

Welded to the stop rod 165 between the lug 163 and the angle 114 is acollar 173. A pair of sealing washers 177 are loosely placed on the stoprod between the collar 173 and the plate 167. At the end of the stop rodopposite the lug 163 is a cushion 179 made of a durable urethanematerial. The cushion 179 is adjustably held to the stop rod by a washerand nuts 180. The locations of the collar 173 and the cushion 179 arechosen to provide positive stops for the headgate 13 at the ready openand exit open modes, respectively. Specifically, rotation of theheadgate in the direction from the closed mode to the ready open mode islimited by the contact of the sealing washers with the plate 167, androtation of the headgate in the direction from the closed mode to theexit open mode is limited by contact of the cushion 179 with the bumper171. The resiliency of the cushion material prevents bounce-back of thegates at the exit open mode.

CABLE MECHANISM

To actuate the control mechanism 14 from a milking station at a divider11, each stall module 8 of the present invention further includes thecable mechanism 85. With particular attention to FIGS. 1, 7, 8, and 14,the cable mechanism comprises a long flexible push-pull cable 136, aclevis 138, a link 142, a post 145, and a linkage rod 147. The cable 136may be entirely conventional, such as is manufactured by the CableControl Division of Tuthill Corporation of Tacoma, Wash.

One end of the cable 136 is installed within a divider 11. The cablepasses in any convenient manner to and is guided through the plate 24 ofthe frame 7 and through the adjacent end wall 28 of the housing 21. Thesecond end of the cable is attached to the clevis 138, which, in turn,is pivotally connected to one end 149 of the link 142. The link issupported for rotation about a horizontal axis 151 by the post 145. Thepost 145 is held to the side wall 111 of the housing 21, as by a screw153. The axis 151 is defined by a shoulder screw 157 screwed into theopposite end of the post as the screw 153. As illustrated, the clevis138 is connected to the end 149 of the link 142 by one end of thelinkage rod 147 and an associated cotter pin 159. The second end of thelinkage rod is connected to the tab 129 of the h-shaped lever 83, whereit is retained in place by a cotter pin 161.

To pivot the first actuating angle 79 to its actuated condition (FIG.11) and thereby enable the gates 31 and 33 to rotate from the closedmode to the ready open mode, the farmer actuates the cable mechanism 85.As illustrated, the farmer pushes a hand knob 131 (FIG. 1) of the cable136 to thereby tilt the h-shaped lever 83 in the direction of arrow 132to a first actuated attitude thereof, FIG. 11. Tilting the lever 83 toits first actuated attitude causes the cross leg 130 thereof to contactthe leg 107 of the first actuating angle 79 and pivot the firstactuating angle to its actuated condition of FIG. 11. For clarity, FIG.11 is shown as having a space between the lever leg 130 and theactuating angle leg 107, but in actuality the lever and actuating angleare in contact.

As soon as the tabs 36 of the gates 33 and 35 have rotated past theraised latch 75, the farmer can release the hand knob 131 of the cable136. Upon doing so, gravity causes the latch 75 to rotate in thedirection of arrow 98 back to its lowered position, FIG. 9. That actioncauses the finger 101 to pull the leg 109 of the first actuating angle79 and pivot the first actuating angle back to its normal condition. Thefirst actuating angle, in turn, tilts the lever 83 back to its normalattitude. Although not shown, springs can be employed to bias the leverto its normal attitude, if desired.

The headgate 13 can be readily returned to its closed mode from theready open mode merely by pushing the gates 31 and 33 in the directionsof arrows 42 of FIG. 5A. When the gate tabs 36 approach the latch 75,which at that point is in its lowered position of FIG. 9, the tabsstrike the latch underside 133 and cam it in the direction of arrow 100.That action also raises the finger 101 within the hole 116, but there isno effect on the first actuating angle 79. As soon as the gate tabsrotate past the latch free edge 89, the latch rotates by gravity to itslowered position of FIG. 9. The gates are then again locked in theclosed mode.

To pivot the second actuating angle 81 to its actuated condition andthereby enable the gates 31 and 33 to rotate to the exit open mode fromthe closed mode, the farmer actuates the cable mechanism 85 by pullingthe hand knob 131 on the cable 136. That action tilts the lever 83counterclockwise, arrow 134, with respect to FIG. 10 to a secondactuated attitude of FIG. 12. As the lever tilts, its cross leg 130contacts the normally vertical leg 121 of the second actuating angle andpivots that actuating angle.

As soon as the gate tabs 36 have been forced past the free edge 89 ofthe latch 77, the farmer releases the cable hand knob 131. Gravity thenrotates the latch 77 to its lowered position. Simultaneously, the latchpulls on the second finger 103 to pivot the second actuating angle backto its normal condition of FIG. 9. The lever 83 also tilts back to itsnormal attitude.

Because of the one degree angle of the axes of rotation 55 of the gates31 and 33 relative to the vertical within the plane 39, the gatesautomatically start to rotate by gravity without external assistancetoward their closed mode from the exit open mode. After the gates haverotated a few degrees, the second angle of six degrees of the axes ofrotation 55 cause the gate to continue to rotate toward the closed mode.As the gates approach the closed mode, the gate tabs 36 contact theunderside 135 of the latch 77 to cam it upwardly and out of the way asthe gates approach the closed mode from the exit open mode.

An important aspect of the present invention is that the cable mechanism85 can be installed in a stall module 8 such that its operation by thefarmer is the same regardless of the divider 11 in which the cable 136and hand knob 131 are located. In FIGS. 1, 7, 8, and 14, the cablemechanism 85 is shown as being installed in a divider that is to theleft of a stall 2 looking in the downstream direction 17. In thatsituation, as described previously, the farmer pushes the hand knob torelease the gates 31 and 33 to rotate to the ready open mode, and pullsthe hand knob to allow rotation of the gates to the exit open mode. Insome situations, it may be more convenient to install the cable 136' andhand knob 131' in the divider that is to the right of the stall. If thecable 136' were connected directly to the lever 83 of the controlmechanism 14, the farmer would have to pull the cable hand knob 131' torelease the gates to rotate to the ready open mode, and push the handknob to allow rotation of the gates to the exit open mode. That is,actuation of the control mechanism by the cable mechanism would bereversed depending on the side of the stall in which the cable and handknob were installed.

To provide consistent actuation of the control mechanism 14 by the cablemechanism 85, a reversing mechanism 183 in the form of the link 142 andassociated components as previously described are provided. Asdescribed, the assembly of the cable mechanism is suitable for actuationfrom a left divider 11. For installation of the cable 136' and hand knob131' in a right divider, the link, post 145, and clevis 138 are moved tothe right of the control mechanism 14 of FIGS. 1, 7, 8, and 14. Inaddition, the clevis is rotatably joined to the second end 181 of thelink. In that manner, the same cable can be used, and the operation ofthe cable mechanism as experienced by the farmer is the same regardlessof the stall in which the cable and hand knob are installed.

HEADGATE EXIT OPEN MODE TO READY OPEN MODE OPERATION

Further in accordance with the present invention, the gates 31 and 33are capable of rotating from the exit open mode all the way to the readyopen mode without stopping and becoming locked at the closed mode.Looking at especially at FIGS. 9-11, a pawl 137 is incorporated into theconnecting bar 74, which preferably is made from a rectangular tube. Thepawl 137 is held between the two side walls of the connecting bar by apin 139 for pivoting in a vertical plane within a slot 144 in theconnecting bar bottom wall 140. Gravity tends to rotate the pawl in aclockwise direction with respect to FIG. 10 about the pin 139. Clockwisepivoting of the pawl is limited by a stop pin 141 pressed into the pawland able to contact the connecting bar bottom wall 140. When the gatesare in the closed mode, the pawl is located over the first actuatingangle 79. In that situation, the pawl rests on the vertical leg 107 ofthe first actuating angle against clockwise rotation about pin 139 dueto gravity.

In FIG. 11, the pawl 137 and the connecting bar 74 are shown in the samelocation as in FIG. 10, even though the control mechanism 14 has beenactuated by the farmer to enable the gates 31 and 33 to rotate towardthe ready open mode from the closed mode. In actuality, the connectingbar and pawl remain in their respective locations shown in FIG. 11 onlyfor an instant after cable mechanism actuation. Because the gate tabs 36constantly push by gravity against the latch 75, as soon as that latchis rotated to its raised position by the tilting of the lever 83, thegates start to rotate. Simultaneously, the connecting bar 74 and pawl137 start to translate generally in the direction of arrow 76.

In FIG. 12 the pawl 137 and the connecting bar 74 are shown at theirrespective locations when the gates 31 and 33 are in their closed modeeven though the control mechanism 14 has been actuated to enable thegates to rotate to the exit open mode from the closed mode. It will berecalled that the gates do not automatically rotate by gravity to theexit open mode from the closed mode merely because the control mechanismis actuated to the condition of FIG. 12. That is because the six degreeangle of tilt of the gates causes them to automatically rotate bygravity only toward the ready open mode from the closed mode; a positiveforce must be exerted against the gates to rotate them to the exit openmode from the closed mode. Consequently, the connecting bar and pawlwill remain in the position shown in FIG. 12 until a force is exerted onthe gates to rotate them toward the exit open mode. When that force isexerted, the connecting bar translates, as mentioned previously, in thegeneral direction of arrow 78.

Now turning to FIGS. 13A-13D, the capability of the gates 31 and 33 torotate all the way from the exit open mode to the ready open modewithout stopping and becoming locked at the closed mode will bedescribed in more detail. In FIG. 13A, it will be assumed that theheadgate 13 is in the closed mode. In that situation, the pawl 137 isover and rests on the vertical leg 107 of the first actuating angle 79similar to FIG. 10. When the gates are in the closed mode, the controlmechanism 14 can be actuated to enable the headgate to operate to eitherthe ready open mode or to the exit open mode.

Actuating the control mechanism 14 to pivot the first actuating angle 79to its actuated condition, FIG. 11, causes the headgate 13 toautomatically rotate by gravity to the ready open mode. Accordingly, thepawl 137 reaches the location relative to the first actuating angle 79as shown in FIG. 13B. FIG. 13B also shows the first actuating anglereturned to its normal condition after the cable mechanism 85 isreleased. When the headgate is pushed back to the closed mode, the pawlis ramped back about the pin 139 by the actuating angle 79 to itslocation shown in FIG. 13A. Consequently, the pawl and first actuatingangle are again at their respective locations shown in FIG. 13A when theheadgate is back at its closed mode.

Actuating the control mechanism 14 to pivot the second actuating angle81 to its actuated condition, FIG. 12, enables the headgate 13 to bepushed to the exit open mode. The pawl 137 then attains the locationrelative to the first actuating angle 79 as shown in FIG. 13C.

In FIG. 13A, dimension x represents the distance the connecting bar 74and the pawl 137 must travel in the direction of arrow 78 from theclosed mode of the headgate 13 toward the exit open mode before the pawlleading corner 143 clears the actuating angle 79. The dimension x ispreferably equivalent to approximately ten degrees of rotation of theheadgate. Consequently, any rotation of the headgate less thanapproximately ten degrees from the closed mode toward the exit open modehas no effect on the pawl. That feature prevents a cow from backing upin the stall after she has started to walk forward until she has walkedfar enough to open the headgate approximately ten degrees.

Because of the compound angle of the axes of rotation 55 of the gates 31and 33, the gates automatically rotate by gravity from the exit openmode of FIG. 13C toward the closed mode. As shown in FIG. 13D, as thepawl 137 approaches the first actuating angle 79 in the direction ofarrow 76, its leading corner 143 contacts the first actuating anglevertical leg 107. Continued rotation of the gates and movement of theconnecting bar 74 causes the pawl to pivot the first actuating angleclockwise with respect to the drawings, FIGS. 11 and 13D. Pivoting thefirst actuating angle clockwise causes it to lift the first finger 101and first latch 75, FIG. 9, such that the latch does not stop gaterotation or lock the gates at the closed mode. Rather, the gatescontinue to rotate past the closed mode all the way to the ready openmode, where they are stopped by the stop mechanism 44.

OPERATION

In use, the walk-through flat barn parlor 1 is able to manage dairy cowsand other large animals with minimum effort by the farmer. It will beassumed that initially the headgate 13 of a stall 2 is in the closedmode. From his workstation at a divider 11, the farmer pushes the handknob 131 or 131' of a cable mechanism 85. The control mechanism 14 thenunlocks the gates 31 and 33 to automatically rotate by gravity to theready open mode. A cow is directed as indicated by arrows 15 to thestall. She steps from the central aisle 6 onto the stall platform 4 andwalks ahead to insert her head and neck into the ready open gates. Asshe walks a little further ahead, her shoulders contact the gates andpush them against gravity to the closed mode. The careful control of thedimension from the frame plane 9 to the vertical platform wall 10assures that the cow walks sufficiently far in the downstream direction17 to fully close and lock the gates while assuring that the cow is at acomfortable stance with all four feet on the platform 4. With the gateslocked in the closed mode by the cooperation of the gate tabs 36 and thelatches 75 and 77, the cow is constrained by its neck within theheadgate. The farmer can then milk or otherwise treat the cow.

When milking is completed, the farmer pulls the cable 136 or 136' by thehand knob 131 or 131' to rotate the latch 77 to its raised position. Thecows are easily conditioned by the sound of the actuating controlmechanism 14 to walk ahead in the downstream direction 17. As describedpreviously, the cow cannot back out of the headgate 13. As the cow walksahead, she pushes the gates 31 and 33 with her shoulders and sides tothe exit open mode. Since only the force of gravity is exerted by thegates on the sides of the cow, the gates are comfortable to walkthrough.

When the cow has fully passed the gates 31 and 33, the compound angle oftheir axes of rotation 55 automatically cause them to rotate by gravityback toward the closed mode. Because of the co-action between the pawl137 and the first actuating angle 79, the gates rotate past the locationof the closed mode and continue on to the ready open mode. The gates arethen ready to accept the next cow without further attention from thefarmer. From that point, the farmer need actuate the control mechanism14 only when subsequent cows are ready to leave the stall 2.

In some instances, however, the cow may not be constrained by theheadgate 13 after she has closed it. That can occur if the cow pushesone of the gates 31 or 33 with her nose or head rather than placing herhead and neck between the gates. In that event, the gates must bereopened to the ready open mode. That is easily accomplished merely bythe farmer pushing the hand knob 131 or 131' to enable the gates torotate open by gravity back to the ready open mode, where they are againready to accept the cow's head and neck. The adjustability provided bythe clevis 166 of the stop mechanism 44 enables the gates to be properlyset at the ready open mode to reliably receive the cows' head and necks.

In summary, the results and advantages of milking parlors can now bemore fully realized. The walk-through flat barn parlor 1 of the presentinvention provides complete management of cows in a convenient and laborsaving manner. This desirable result comes from using the cablemechanism 85 that operates from the farmer's normal workstation at thedividers 11, which are distant from the headgate 13. The cable mechanismselectively controls the headgate to rotate between closed, ready open,and exit open modes. Gravity acts on the headgate to automaticallyoperate it to the ready open mode from either the closed or the exitmodes. The cows themselves operate the headgate from the ready open modeto the closed mode, and from the closed mode to the exit open mode asshe enters and leaves a stall 2 in a straight-ahead manner. Theinvention therefore greatly improves labor efficiency as measured bycows milked per unit time.

It will also be appreciated that in addition to the superior performanceof the walk-through flat barn parlor 1, its construction is such thatits cost is little if any greater as compared to traditional milkingparlors. Since the mechanical components are simple and few in number,the need for maintenance is minimal. Another important advantage is thatthe adjustable and swivelable stools 29 enable the farmer to comfortablysit at his milking station without slowing the milking process.

Thus, it is apparent that there has been provided, in accordance withthe invention, a walk-through flat barn parlor that fully satisfies theaims and advantages set forth above. While the invention has beendescribed in conjunction with specific embodiments thereof, it isevident that many alternatives, modifications, and variations will beapparent to those skilled in the art in light of the foregoingdescription. Accordingly, it is intended to embrace all suchalternatives, modifications, and variations as fall within the spiritand broad scope of the appended claims.

We claim:
 1. A walk-through flat barn parlor comprising:a. a pluralityof elongated frames upstanding from a floor and extending end-to-endalong a vertical plane; b. divider means mounted to adjacent frames fordefining workstations; c. gate means supported by each frame forautomatic operation by gravity between a closed mode whereat the gatemeans constrains the animal by its neck and a ready open mode whereatthe gate means can accept the head and neck of an animal walking theretofrom an upstream direction, and for forced operation between the closedmode and an exit open mode whereat the gate means releases the animal towalk therefrom in a downstream direction; and d. control means forselectively controlling the gate means from a workstation remote fromthe gate means to automatically operate by gravity from the closed modeto the ready open mode and for forced operation from the closed mode tothe exit open mode.
 2. The walk-through flat barn parlor of claim 1wherein the gate means further operates automatically by gravity fromthe exit open mode to the ready open mode.
 3. The walk-through flat barnparlor of claim 2 wherein the gate means comprises:a. first and secondgates hinged to each frame for rotating about first and second axes ofrotation, respectively, the first and second axes of rotation lying in aplane that makes an angle with the vertical plane directed upwardlytoward the upstream direction, the gates having respective horizontaltop tubes; and b. first and second tabs upstanding from the respectivehorizontal top tubes of the first and second gates.
 4. The walk-throughflat barn parlor of claim 3 wherein the first and second axes ofrotation converge upwardly,so that the first and second axes of rotationmake respective compound angles with the vertical plane.
 5. Thewalk-through flat barn parlor of claim 4 wherein the control meanscomprises:a. a control mechanism assembled to the frame selectivelyco-acting with the first and second tabs of the first and second gates,respectively; and b. a flexible cable fastened to the control mechanismfor being bidirectionally actuated from the workstation to selectivelyproduce a first co-action between the control mechanism and the gatetabs that enables automatic rotation of the gates by gravity from theclosed mode to the ready open mode, and second co-action between thecontrol mechanism and the gate tabs that enables forced rotation of thegates from the closed mode to the exit open mode.
 6. The walk-throughflat barn parlor of claim 5 wherein:a. each frame comprises:i. aplurality of posts upstanding from the floor; and ii. a housingextending between and secured to the posts; b. each gate means furthercomprises first bearing means attached to selected frame posts forsupporting lower ends of the first and second gates, the first bearingmeans comprising:i. a pair of brackets attached to selected frame posts,each bracket having a leg that lies in a plane perpendicular to the axisof rotation of the associated gate; ii. a pair of cylindrical plugs ofselected bearing material; and iii. means for removably fastening thecylindrical plugs to associated bracket legs; c. each gate is formedwith a cylindrical recess that fits over and is guided for rotation onan associated cylindrical plug; and d. the gate means further comprisessecond bearing means within the frame housing for journaling upper endsof the first and second gates, the first and second bearing meanscooperating to define the first and second axes of rotation of the firstand second gates, respectively.
 7. The walk-through flat barn parlor ofclaim 5 wherein the control mechanism comprises:a. actuator meansassembled to the frame for being bidirectionally pivoted by the flexiblecable; and b. latch means rotatingly mounted to the frame forselectively capturing and releasing the tabs of the first and secondgates therebetween in response to pivoting of the actuating means by theflexible cable, so that rotation of the first and second gates abouttheir respective axes of rotation is controlled by the cooperation ofthe actuator means, flexible cable, and latch means.
 8. The walk-throughflat barn parlor of claim 7 wherein:a. the actuator means comprises:i. afirst actuating angle assembled within the frame for pivoting betweenfirst and second conditions; ii. a second actuating angle assembledwithin the frame for pivoting between first and second conditions; andiii. lever means assembled within the frame for selectively tiltingbetween first, second, and third attitudes in response to selectedactuation of the cable means; and b. the latch means comprises:i. afirst latch mounted to the frame for rotating between first and secondpositions in response to pivoting of the first actuating angle; and ii.a second latch mounted to the frame for rotation between first andsecond positions in response to pivoting of the second actuating angle,the first and second latches being in their respective first positionsto capture the tabs of the first and second gates between them andthereby lock the gates in the closed mode when the lever means is in thefirst attitude thereof and the first actuating angle and the secondactuating angle are in their respective first conditions, the firstlatch being in the second position thereof and the second latch being inthe first position thereof to unlock the gates for automaticallyrotating by gravity to the ready open mode when the lever means is inthe second attitude thereof and the first actuating angle is in thesecond condition thereof and the second actuating angle is in the firstcondition thereof, the first latch being in the first position thereofand the second latch being in the second position thereof to unlock thegates to be forcibly rotated to the exit open mode from the closed modewhen the lever means is in the third attitude thereof and the firstactuating angle is in the first condition thereof and the secondactuating angle is in the second condition thereof.
 9. The walk-throughflat barn parlor of claim 8 wherein the latch means further comprises:a.a first finger joined to the first latch and having a hook thatcooperates with the first actuating angle to rotate the first latch inresponse to pivoting of the first actuating angle; and b. a secondfinger joined to the second latch and having a hook that cooperates withthe second actuating angle to rotate the second latch in response topivoting of the second actuating angle.
 10. The walk-through flat barnparlor of claim 8 further comprising pawl means for pivoting the firstactuating angle from the first to the second conditions thereof andthereby rotate the first latch from the first to the second positionsthereof when the first and second gates rotate from the exit open modetoward the closed mode,so that the first and second gates canautomatically rotate by gravity from the exit open mode to the readyopen mode.
 11. The walk-through flat barn parlor of claim 10 wherein:a.the gate means further comprises bar means connecting the first andsecond gates to each other for directing the gates to rotate togetherand in opposite directions; and b. the pawl means comprises a pawlpivotally held in the bar means, the pawl striking the first actuatedangle to pivot it from the first to the second condition thereof whenthe first and second gates rotate from the exit open mode toward theclosed mode.
 12. The walk-through flat barn parlor of claim 7 furthercomprising pawl means for cooperating with the actuator means and thelatch means to enable the first and second gates to automatically rotateby gravity from the exit open mode to the ready open mode.
 13. Thewalk-through flat barn parlor of claim 4 further comprising pawl meansfor selectively co-acting with the control means to enable the gatemeans to automatically rotate by gravity from the exit open mode to theready open mode.
 14. The walk-through flat barn parlor of claim 2wherein the control means comprises;a. a control mechanism assembled tothe frame in operative association with the gate means; and b. cablemeans bidirectionally actuated from the workstation for selectivelyactuating the control means to enable automatic operation of the gatemeans by gravity from the closed mode to the ready open mode and forcedoperation of the gate means from the closed mode to the exit open mode.15. The walk-through flat barn parlor of claim 14 wherein the cablemeans comprises reversing means for enabling the cable means toconsistently actuate the control mechanism means from differentworkstations at the divider means.
 16. The walk-through flat barn parlorof claim 14 wherein the cable means comprises:a. an elongated flexiblecable installed within a selected divider means and having an actuatingend proximate the workstation in the divider means and a second end; andb. a reversing mechanism connected between the flexible cable second endand the control mechanism, the reversing mechanism being selectivelyassemblable to the frame to enable consistent actuation of the controlmechanism from the flexible cable actuating end independent of thelocation of the workstation at the divider means.
 17. The walk-throughflat barn parlor of claim 1 wherein the floor is formed as a platformupraised from an adjacent aisle, the platform having a vertical walladjacent the aisle that is at a controlled distance from the gate meansto assure that the animal walks from the upstream direction completelyand comfortably onto the platform and to the gate means when the gatemeans is at the closed mode thereof.
 18. A modular stall for managingcow traffic in a downstream direction comprising:a. frame means lyinggenerally along a vertical plane for defining a workstation for aperson; b. first and second gates mounted to the frame means, each gatebeing rotatable about a single respective axis of rotation betweenclosed, ready open, and exit open modes, the gates being locked andlying in a second plane that makes an angle with the vertical planedirected upwardly in an upstream direction when the gates are in theclosed mode, the gates being opened in the upstream direction when theyare in the ready open mode, the gates being opened in the downstreamdirection when they are in the exit open mode; and c. control means forselectively locking the gates at the closed mode, unlocking the gates toautomatically rotate by gravity from the closed mode to the ready openmode, and unlocking the gates to be pushed from the closed mode to theexit open mode, so that a cow can walk in the downstream direction toand put her head and neck through the gates when the gates are in theready open mode and push the gates to the closed mode for lockingthereat and thereby constraining the cow in place, and the control meanscan unlock the gates to enable the cow to walk in the downstreamdirection and push the gates from the closed mode to the exit open mode.19. The modular stall of claim 18 wherein the axes of rotation of thegates converge upwardly within the second plane to thereby enable thegates to rotate automatically by gravity from the exit open mode towardthe closed mode.
 20. The modular stall of claim 19 wherein:a. the secondplane makes an angle of approximately six degrees with the first plane;and b. the axes of rotation of the first and second gates convergeupwardly at an included angle of approximately two degrees.
 21. Themodular stall of claim 18 wherein the control means comprises pawl meansfor cooperating with the control means to enable the gates to rotatefrom the exit open mode to the ready open mode without becoming lockedat the closed mode.
 22. The modular stall of claim 21 wherein:a. thefirst and second gates have respective tabs upstanding therefrom; b. thecontrol means comprises first and second latches assembled within theframe means for rotating between lowered and raised positions, the gatetabs being captured between the latches when the latches are in theirrespective lowered positions and the gates are in the closed mode; andc. the control means further comprises:i. first and second actuatingangles assembled to the frame means for pivoting between respectivenormal and first conditions; ii. first and second finger means joined tothe first and second latches, respectively, for rotating the latches inresponse to pivoting of the first and second actuating angles,respectively; iii. lever means assembled to the frame means for pivotingthe first and second actuating angles between their respective normaland first conditions; and iv. cable means attached to the lever meansfor selectively tilting the lever means between normal, first, andsecond attitudes from the workstation, the latches being in theirrespective lowered positions to capture the gate tabs therebetween whenthe first and second actuating angles are in their respective normalconditions, the first latch being in the raised position thereof torelease the gates to rotate to the ready open mode when the lever meanspivots the first actuating angle to the first condition thereof, and thesecond latch being in the raised position thereof to release the gatesto rotate to the exit open mode when the lever means pivots the secondactuating angle to the second condition thereof.
 23. The modular stallof claim 22 wherein:a. the gates are connected to each other by aconnecting bar; and b. the pawl means comprises a pawl pivotally held inthe connecting bar, the pawl co-acting with the first actuating angle topivot it from the normal to the first condition thereof when the gatesrotate toward the closed mode from the exit open mode to thereby enablethe gates to rotate from the exit open mode to the ready open modewithout the lever pivoting the first actuating angle.
 24. The modularstall of claim 18 wherein:a. the first and second gates have respectivetabs upstanding therefrom; and b. the control means comprises:i. firstand second actuating means assembled to the frame means for pivotingbetween respective normal and actuated conditions; ii. first and secondlatch means assembled to the frame means for rotating between respectiveraised and lowered positions and for cooperating with each other tocapture the gate tabs between them and thereby lock the gates in theclosed mode when the first and second latch means are in theirrespective lowered positions, the first and second latch means being intheir respective lowered positions when the first and second actuatingmeans are in their respective normal conditions, the gates beingreleased to automatically rotate by gravity to the ready open mode whenthe first latch means is in the raised position, the first latch meansbeing rotated to the raised position thereof in response to the firstactuating means being pivoted to the actuated condition thereof, and thegate being released to rotate to the exit open mode when the secondlatch means is in the raised position thereof, the second latch meansbeing rotated to the raised position thereof in response to the secondactuating means being pivoted to the actuated condition thereof; andiii. lever means for selectively pivoting the first and second actuatingmeans between their respective normal and actuated conditions.
 25. Themodular stall of claim 24 further comprising pawl means associated withthe first and second gates for pivoting the first actuating means to theactuated condition thereof when the gates rotate from the exit open modetoward the closed mode to thereby rotate the first latch means to theraised position thereof without pivoting the first actuating means bythe lever means.
 26. The modular stall of claim 24 wherein the controlmeans further comprises cable means for tilting the lever means toselectively pivot the first or second actuating means.
 27. A method ofmanaging large animals comprising the steps of:a. locking headgates in aclosed mode at an animal stall; b. actuating a control mechanism in afirst manner and unlocking the headgates; c. automatically rotating theheadgates by gravity from the closed mode to a ready open mode; d.walking an animal along a path from an upstream direction to theheadgates and walking her ahead to push the headgates to the closed modeand locking the headgates at the closed mode; e. actuating the controlmechanism in a second manner and unlocking the headgates; f. walking theanimal in a downstream direction and pushing the headgates to an exitopen mode; and g. automatically rotating the headgates by gravity fromthe exit open mode to the ready open mode.
 28. The method of claim 27wherein the step of automatically rotating the headgates by gravity fromthe closed mode to the ready open mode comprises the step of biasing theheadgates while they are in the closed mode to rotate by gravity to theready open mode.
 29. The method of claim 28 wherein the step ofautomatically rotating the headgates by gravity from the exit open modeto the ready open mode comprises the steps of:a. biasing the headgatesto rotate by gravity toward the closed mode from the exit open mode; b.connecting the headgates with a connecting bar having a pawl thereon;and c. controlling the first latch mechanism by the pawl to release theheadgates for rotation to the ready open mode as the headgates approachthe closed mode from the exit open mode.
 30. The method of claim 27wherein the step of actuating the control mechanism in a first mannerand unlocking the headgates comprises the steps of:a. installing a cablemechanism having an actuating end at a first workstation lying on afirst side of the path and connecting the cable mechanism to the controlmechanism; b. actuating the cable mechanism at the actuating end thereofin the first manner; c. installing the cable mechanism with theactuating end thereof at a second workstation on a second side of thepath and connecting the cable mechanism to the control mechanism; and d.actuating the cable mechanism at the actuating end thereof in the firstmanner, so that the animals are managed from the first and secondworkstations by consistent actuation of the cable mechanism.